Two-zone pumping system with gas anchor



I invention relates wise.

Patented Mar. 7, 1950 'rwo-zom: rmurnm srsm'wrrm ass .mcnon Clarence J. Coberly, Loo Angela, Callih, asllgnor to Kobe, Ina, Huntington Park,

, poration of California Annamaria; 2a, 1945. Serial No. 001,520

11 101. lo -4s),

to the well pumping art.

and more particularly to a fluid-operated well Pumping device adapted to alternatively pump' oil from any one or more of a plurality of producing well strata in a well, as desired.

The invention is of particular utility in the oil industry in the production of 'oil wells and is particularly useful ,in combination with a fluidoperated well pump, and, consequently, it will be described in connection therewith, although it will be understood that the invention is susceptible of other uses and I do not intend to be limited to the speciflc embodiment disclosed and described herein.

Oil wells commonly include several independent strata from which oil may be produced. Usually when an oil well is drilled, it is intended to produce from a particular known-stratum, al-

CaliL, a corboth of two producing well strata, in which the flow from the strata or stratum, as the case may be, is freed of entrained gas before it is conveyed to the pump inlet. To accomplish this, I prefer to provide a fluid reservoir at atmospheric or casing head pressure into which the flow from the well strata is discharged to permit the separation therefrom of the entrained gas, the pump inlet being connected with the bottom of the reservoir so that the well fluid therefrom is conveyed to the-pump under a substantial pressure created by the head of well fluid in the reservoir. I Another object of the invention is to provide a two-zone pumping apparatus as generally deii scribed above, in which the flow from the rethough frequently there are other shallower producing strata in the well but oi less desirable characteristics. For example, the shallower strata may be of low productivity. or the" oil therefrom may be of inferior quality. Consequently, it is the usual practice to produce from the most desirable stratum until such timeas it becomes uneconomical and then to close of! such stratum and produce from an upper stratum of the well. Sometimes the oil from several strata is allowed to flow into and mix in the well, and

the mixture'is produced by pumping or other- Such practices are often undesirable, and it is a primary object of my present invention to provide an apparatus by which several well strata may be separately but alternatively produced, preferably by pumping therefrom, so that the relative production from the several strata may be governed and controlled, as de-- sired.

Another object of the invention is to provide an apparatus whereby the flow from several well as to attain a mixture having predetermined characteristics, and then to pump the mixture to the surface of the well by suitable pumping means.

A further object of my invention is to provide a packer in a well between producing strata, separating the same into upper and lower production zones, providing valve means communicating with both zones, and providing a well tubing having an inlet adapted to cooperate with the valve means to connectselectiyeiy the inlet with either or both zones.

Still another object of the invention is to provide an apparatus for pumping from either or strata may be mixed indesired proportions, so

spective well zones is controlled by vertically moving the power tubing'relative to the production tubing, the fluid-operated pump being moved with the power tubing.

A futher object of the invention is to provide a two-zone pumping apparatus and a power tubing, in which one of the tubings is vertically movable relative to the other to control the proportion of flow from each of the production zones, there being mechanical apparatus provided for causing such vertical movement of the movable tubing. As it is desirable to effect such movement of the movable tubing during pumping operation and without cessation thereof, I

provide a novel form of casing head adaptedto accomplish this, and this is a further object of the invention.

Other objects and advantages will be apparent from the following specification and the drawings, which are for the purpose of illustration only, and in which:

Fig. l is a diagrammatic assembly view, showing my invention installed in a well;

Fig. 2 is a vertical sectional view of the casing head of the invention;

Fig. 3 is a vertical sectional view of the device extending downwardly from the bottom of Fig. 2;

Fig. 4. is a vertical sectional view of the device extending downwardly from the bottom of Fig. 3;

Fig; 5 is a vertical sectional view extending downwardly from the bottom of Fig. 4;

Fig. 6 is a cross-sectional view taken on the line'8-8 of Fig. 2;

Fig. '7 is a cross-sectional view taken on the line 1-7 of Fig. 3;

Fig. 8 is a cross-sectional view taken on the line a-: of Fi 4;

. Fig.9 is a cross-sectional view taken on'the line 99 of Fig. 4; Fig. 10 is a vertical sectional view of a portion of the invention showing the valve mechanism thereof in one operating position;

Fig. 11 is a vertical sectional view similar to Fig. 10, but showing the valve mechanism in an alternative operating position; and

Fig. 12 is a vertical sectional view similar to Fig. 10, but showing the valve mechanism in another alternative operating position.

Referring to the drawings, Fig. 1 shows an oil well ill having a casing it set therein in the customary manner, the casing having perforations l1 therein disposed to register with an upper producing well stratum A, and having perforations I8 therein adapted to register with a lower producing well stratum B. The upper end of the casing i is provided with a casing head I! from which a production tubing extends downwardly into the well. Connected to the lower end of the production tubing 20, and extending downwardly therefrom in the well I5. is mechanism to be described hereinafter, which includes an upper well packer 2|, preferably of the swab type, and a lower well packer 22, preferably of the hook-wall type well known in the art. The upper well packer 2i forms a fluidtight seal with the inner wall of the casing l6 so as to provide therein a reservoir well zone 23. Similarly, the lower well packer-22 forms a fluidtight seal with the inner wall of the casing l5 and divides the casing below the upper well packer 2| into an upper well zone 24 communicating through the perforations I! with the upper producing well stratum A, and a lower well zone 25 communincating through the perforations II with the lower producing well stratum B.

Referring to Fig. 2 of the drawings, the casing head 18 includes a bottom plate 21 provided with a tubular portion 28 in which the upper end of the casing I6 is threaded, the bottom plate being suitably secured as by bolts 29 to a lower body member 30 of the casing head. The lower face of the lower body member 30 has dependingtherefrom a tubular portion 3| to which is secured, as by means of a collar 22, the upper'end of the producing tubing 20. The upper end of the lower body member 30 is provided with a central bore 33 which receives a tubular sleeve 35 passing therethrough, the lower portion of the central bore 33 being provided .with a counterbore 36 so as to form an annular fluid passage 31 between the tubular sleeve 55 and the counterbore 38. The upper portion of the lower body member 30 is provided with a radial discharge port 38 which communicates with the annular fluid passage 31 and with a discharge tubing 39 leading to a suitable point of disposal or use (not shown).

Secured to the upper end of the lower body member 30, as by bolts 4|, is an upper body member 42 of the casing head I 9, the upper body member being provided with a central bore 45 axially aligned with the central bore 33, through which extends the upper end 44 of a power tubing 45, the central bore 43 being provided with a counterbore 46 forming an annular fluid passage 41 between the counterbore and the power tubing 45. The upper body member 42 is provided with a radial inlet port 48 communicating between the annular fluid passage 41 and a supply tubing 49, the supply tubing leading to a suitable source of fluid under high pressure (not shown). The upper end of the tubular sleeve 35 is received in a counterbore 5c of the upper body member 42, the inner diameter of the sleeve 35' being approximately equal to the diameter of the counterbore 44 so that the annular fluid passage 41 extends downwardly between the power tubing 45 and the inner wall of the sleeve. A packing gland II is provided in the upper end of 5 the upper body member 42 to provide a fluidtight seal between the body member and the power tubing 45 passing therethrough.

Secured to the upper end of the upper body member 42 as, by a set-screw 5!, is a tubular 10 member 54 having an annular supporting ring 55 welded or otherwise secured to the inner wall thereof and which supports a ball bearing 55 which in turn supports a rotatable gear wheel 51 having gear teeth 5. on the periphery thereof 15 adapted to be engaged by. a pinion 59 provided on a rotatable shaft 50. The gear wheel 51 is provided with a threaded opening 6! therethrough which receives square threads 62 formed on the power tubing 45. As will be appreciated,

20 rotation of the shaft 60 and the pinion 55 causes rotation of the gear wheel 51, to raise or lower the power tubing 45, depending upon the direction of rotation of the gear wheel. Threaded on the upper end of the power tubing 45 is a closure 5 plug 64 having an end plug 64 threaded thereto and adapted for engagement by conventional well rig tools for pulling the tubing, as is well known in the art. As will also be noted, the

lowermost portion of the power tubing 45 seen in 30 Fig. 2 is provided with a plurality of radial ports 55 which provide fluid communication between the annular fluid passage 41 and vthe interior of the power tubing 45.

Referring to the upper portion of Fig. 3, the 5 lower end of the tubular sleeve 25 is threaded to an annular plug 41 which retains a chevron packing 68 adapted to form a fluid-tight seal -between the tubular sleeve and the outer wall of the power tubing 45. Connected to the lower end of the power tubing 45, and adapted to be supplied with operating fluid under high pressure therefrom, is a fluid-operated pump unit 69, comprising the pumping means of the invention, which has discharge ports 10 which communicate with the interior of the production tubing 20, the fluid-operated pump unit being of any type well known in the art. The lower end of the fluid-operated pump unit 85 has threaded therein an annular inlet member H which is adapted to be supported by a tubular sleeve 12 which is threaded into the lower end of the production tubing 25. Threaded into the pump inlet member II and extending downwardly therefrom is a tubular valve member 13 which makes a close sliding flt with the bore 14 of the sleeve 12. Thus. engagement of the pump inlet member H with the upper end of the sleeve 12 limits downward movement of the fluid-operated pump 89 relative to the production tubing 50 20, but permits upward movement therebetween. Threaded to the lower end of the tubular sleeve 12 is an upper tubular valve body 18 having radial ports 11 which communicate with registering ports 18 of a sleeve 19 carried on the outer wall of the upper valve body 18. The sleeve 19 is retained in place on the upper valve body 18 by an upper ollar threaded to the upper valve body and a lower collar 8| (shown in Fig. 4)

welded or otherwise secured thereto. The lower 7 portion of the sleeve 15 is reduced in diameter to cooperate with a bore 23 of a tubular packer element 54 to deflne an annular passa e therebetween. The lower nortion of the tubular member 13 has a portion 55 of reduced diameter, 75 forming an annular fluid passage 81 adapted to aeeaeee 8 communicate between the radial ports ll of the upper tubular valve body 13 and radial ports 33 formed in the tubular member. As will also be noted, the upper end of the annular fluid passage 28 communicates with circumferentially spaced longitudinal ports 33, the upper ends of which communicate with the interior of an upwardly extending tube 3!, the upper end of which is open to the casing I3. Carried on the tubular packer element 84 is the upper well packer 2I which is held in longitudinal position ,thereon by a sleeve 32, the lower end of which, as seen in Fig. 4,- abuts against a collar 23 threaded to the lower end of the tubular packer element ll.

Referring to Fig. 4, the lower end of the upper tubular valve body. I3 is provided ,with an enlarged head 34 which abutsagainst the upper end of an intermediate valve body 33, the lower end of which abuts against the upper end of alower valve body 33, the upper valve body 13, the intermediate valve body 3|, and the lower valve body 80 being rigidly secured in axial alignment by a longitudinal tie bolt 31. The head 94 is provided with a longitudinally drilled-passage 93 which is axially alignedwith a 101181- tudinal bore 33 formed in the intermediate valve body 35 and-with a longitudinally drilled passage lot in the lower valve body 33. Disposed in the bore 99 is a compression spring I32, the upper end of which engages an upper spring follower I03 and the lower,end of which engages a lower spring follower Ill, the upper spring follower supporting an annular valve cup'lli which in turn supports an upper ballvalve member Ill, and the lower spring follower ill engages an annular valve cup I31 which in turn engages a lower ball valve member I33. As will be understood, the spring I32 normally retains the upper ball valve member I33 in engaBement with the drilled passage 33 to close the same, and

maintains the lower ball valve member li'l'in '6 upperendwith the tiallyspecedradialports I23, the inner endsof which communicate with a bore I26 formed in the foot member II3.

The lower end of the tubular member I3 is closed by a plug I2l threadedly secured thereto, the plug alsohaving threaded thereto and depending therefrom a tubular valve element I23 which makes a'close sliding fluid-tight fit in the central bores of the upper tubular valve body I3. the intermediate valve body 0!, and the lower valve body 33, the lower end of the valve element being open so as to communicate with the radial P rts I23 of the foot member II3. The central portion of the valve element I23 is reduced in diameter to provide an annular channel I29, the upper ad of which communicates with an upper hell groove I30, and the lower end of which communicates with a lower helical groove I3I,

and radial ports I32 are provided to communiv cate between the channel I29 and the interior of the valve element. The upper helical groove inai'ter.

engagement with the passage Hill to close it. The

lower end of the head 33 is counterbored to provide an upper chamber III in which the upper ball valve member I03 is disposed, and the upper end of the lower valve body 33 is counterbcred to provide a lower chamber III in which the lower ball valve member I03 is disposed. The lower valve body 86 is also provided with a depending tubular extension II 2, the lower end of whichis threaded into a foot member II3.

Clamped between the lower valve body 33 and the foot member I I3 is a tubular sleeve I it which defines an annular passage II! communicating between the longitudinally drilled passage -I33 of the lower valve body 33 and a plurality of circumferentially spaced longitudinal passages 8 provided in the foot member. Also carried by the foot member I I3 is an upwardly extending tubular sleeve H8, the upper end of which makes a. sliding fit into the lower end of the tubularpacker' element 81 and is provided with perforations H9. The tubular sleeve 3 cooperates with the sleeve III to form an annular fluid passage I20 therebetween-which communicates at its upper end with the longitudinally drilled passage 98 of the head 98, and which communicates at its lower end with a plurality of circumferentially spaced longitudinal passages I2I formed in the foot member M3.

Also carried by the foot member I I3 is an outer tubular sleeve I22. the upper end of which is secured, as by welding or otherwise; to the 'collar 93, which withthe sleeve Ill forms an annular passage I23 therebetween communicating at its Connected to and depending from the foot member I I3 is a tubing section I33 having perforations I 33 therein which provide communication between the interior of the tubing section and the upper well zone 24. Also threaded to the lower portion of the foot member H3 is an inlet tubing I35 which, together with the tubing section I33, defines an annular fluid passage I33 therebetween which communicates at its upper end withthe longitudinal passages I2I of the foot member. The interior of the inlet tubing I33 communicates at its upper end with the longitudinal passages II! of the foot member.

As seen in Fig. 5, the lower end of the tubing section I33 is threaded into the upper end of the lower well packer, 22 which engages the inner wall of the casing It to form a fluid-tight seal therewith, the packer being provided at its lower end with a depending bull plug I3! having perforations I38 therein which provide communication between theinteridr of the bull plug and the lower well zone 28. The lower portion of the inlet tubing I3i extends downwardly through the lower well packer 22 and into the bull plug I31 to a point adjacent the lower end of the bull plug, as best seen in Fig. 1, the bull plug and inlet tubing forming a gas anchor, as will be understood by those skilled in the art.

With the bottom hole parts of the device assembled as illustrated in Figs. 3, 4, and 5, it will be noted that the inlet member H of the fluidoperated pump unit 69 engages and is supported on the top of the tubular sleeve 12, in which position the valve element I28, as seen in Fig. 4, is so disposed relative to the valve bodies I6, 95,

and 96 that the annular channel I29 on the valve element I 28 is out of communication with the chambers III! and Hi, and consequently no fluid may flow from either of the drilled passages 38 or Hill to the interior of the valve element. Normally, it is preferable to install the unit in a well with the parts in the position just described.

In operation, if it is desired to pump at full capacity from the lower well zone 25, the power tubing 35 is vertically positioned relative to the production tubing 20 so that the valve element I23,is disposed relative to the valve bodies 13,

perforations Illand com municating at its lower end with circumferen- 7 and 88 as illustrated in Fig. 10, in which the annular channel I28 registers directly with the lower chamber I I I. Operating fluid, such as oil under high pressure, is delivered through the power tubing 45 to the fluid-operated pump unit 88 so as to actuate the same as is well known in the art. Well fluid then flows from the lower producing zone B through the perforations I8 in the casing I into the lower well zone 25, and

flows therefrom through the bull plug I31 and the inlet tubing I35, comprising a gas anchor of the invention, into the inlet tubing. Such well fluid from the lower well zone 25 flows from the inlet tubing I35 upwardly through the longitudinal passages II8 of the foot member II3 into the annular passage H5 and upwardly therethrough and into the longitudinally drilled passage IIIII in the lower valve body 96. The well fluid then raises the lower ball valve member I88 and flows through the lower chamber III into the annular channel I28. From the annular channel I29 the well fluid flows through the radial ports I32 into the tubular valve element I28 and downwardly therethrough into the depending tubular extension II2. From the tubular extension II2 well fluid flows outwardly through the radial ports I24 in the foot member II3 into the annular fluid passage I23 and upwardly therethrough. From the upper end of the annular fluid passage I23 the well fluid flows inwardly through the perforations I I8 of the tubular sleeve II8 into the annular fluid passage 85, through which it flows upwardly to discharge through the longitudinal ports 89 into the lower end of the upwardly extending tube 98, through which it in turn flows upwardly to discharge into the reservoir well zone 23. Since the upper end of the upwardly extending tube 90 is at all times above the liquid level in the reservoir well zone 23, any gas mixed with the well fluid can separate therefrom and pass upwardly through the casing I6 between the casing and the production tubing 20.

Well fluid flows from the lower portion of the reservoir well zone 23 inwardly through the radial ports 82 formed in the tubular packer element 84 and through the ports I8 and TI to the annular fluid passage 81 through which it flows downwardly to enter the tubular member I8 through the radial ports 88. The well fluid then flows upwardly through the tubular member 13 to enter the fluid-operated pump unit 58 through the annular inlet member II. As will be noted, the inlet member II of the fluid-operated pump unit 58 is disposed at all times below the upper liquid level of well fluid in the reservoir well zone 23, so that the fluid in such zone entering the fluid-operated pump unit is at all times under some pressure so as to maintain any gas therein in solution, to provide maximum volumetric efllciency of the fluid-operated pump unit 88, which is another feature of the invention.

Well fluid is discharged from the fluid-operated pump unit 88 through the discharge ports III thereof into the production tubing 28, being pumped upwardly therethrough to pass through the annular fluid passage 81 of the casing head is and discharging through the radial discharge port 88 into the discharge tubing 88 to be conveyed to a suitable point of use or disposal (not shown).

The position 01' the tubular valve member I28 shown in Fig. may be referred to as a first operating position, in which the full flow from the lower well zone is produced by the fluid-operated pump unit 88. In this position, it will be noted, the upper helical groove I88 does not register with the upper chamber H8. and consequently, as will be seen hereinafter, no well fluid is produced in this position from the upp r well zone 24. It will also be understood that in the event that less than full flow of the production from the lower well zone" is desired, the tubular valve element I28 may be lowered so as to cause the upper helical groove I88 to register with the lower chamber III, in which case the flow from the lower well zone is throttled by the restricted cross-sectional area of the upper helical groove. As will be obvious, since the cross-sectional area 01 the upper helical groove I88 is reduced as it extends upwardly, any desired variation in the flow from the lower well zone may be obtained by suitable positioning of the valve element I28.

Adjustment of the tubular valve element I28, by vertical movement thereof, is accomplished by raising or lowering the power tubing 45,- which is accomplished by actuation of the special casing head I8, as best shown in Fig. 2. Since the upper end 44 of the power tubing 45 is threadedly secured to the gear wheel 51, rotation of the gear wheel, by rotation of the shaft 88 and the pinion 59, provides the desired vertical adjustment of the power tubing 45. When the power tubing 45 is raised so as to move the fluid-operated pump unit 58 out of engagement with the tubular sleeve I2, upon which it rests as shown in Fig. 3, the full weight of the power tubing and pump will be supported by the gear wheel 51, which in turn is rotatably supported by the thrust bearing 58. Thus, the casing head I8 provides mechanical means for vertically adjusting the position of the power tubing 45 relative to the production tubing 28 whereby production from the well is controlled as desired.

Operating fluid, such as oil under high pressure, is conveyed to the fluid-operated pump unit 68 through the power tubing 45 to operate the pump unit, as is well known in the art. Such operating fluid passes through the casing head I8, bein introduced thereinto from the supply tubing 48 and passing through the radial inlet port 48, the annular fluid passage 41, and the radial ports into the power tubing 45, through which it flows downwardly to the fluid-operated pump unit 88.

with the parts in the position illustrated in Fig. 11, which may be termed a second operating position, the annular channel I28 of the tubular valve element I28 registers with both the upper chamber H0 and the lower chamber III so as to permit well fluid from both the upper well zone 24 and the lower well zone 25 to flow to the fluidoperated pump unit 88. Flow from the lower well zone 25 is as described above in connection with Fig. 10. Fluid from the upper well producing stratum A flows through the perforations I! of the casing I8 into the upper well zone 24, passing inwardly through the perforations I84 into the tubing section I88. Such well fluid from the upper well zone passes through the annular fluid channel I88 and upwardly therethrough and through the longitudinal passages I2I oi the foot member II8 to the annular fluid passage I28, through which it flows upwardly to enter the longitudinally drilled passage 88 of the head 84. Such well fluid displaces the ball valve member I88 from its seated position as illustrated in Fig. 4, to flow into the upper chamber III! and thence through the annular channel I 28 and the radial ports I82 to the interior of the tubular valve element I28, commingllng with the well fluid from the lower well zone 2!. Thus, in this second opmunication with both the upper and lower well zones 24 and 25, and well fluid is pumped from both zones.

In the position illustrated in Fig. 12, which may be termed a third operating position, the tubular valve .element i2! is adjusted vertically to a position in which the annular channel I29 thereof communicates only with the upper chamber 0, the lower helical groove i3! being out of communication with the lower chamber III. In this third operating position well fluid from the upper well zone 24 may flow directly to the fluidoperated pump unit 69, as described above, but the lower well zone 25 is closed off from communication therewith. Thus, in this position only the upper well zone 24 will be produced. bviously, the tubular valve element I28 may be positioned intermediate the positions illustrated in Figs. 11 and 12, in which the annular channel I29 communicates with the upper chamber H0 and the lower helical groove I3l communicates with the lower chamber ill, in which intermediate position the full flow from the upper well zone 24 will be produced, but only a restricted flow from the lower well zone 25. will be admitted through the lowerv helical groove.

Other intermediate operating positions in which the tubular valve element I28 may be positioned will be apparent to those skilled in the art, and it will be understood that the invention provides means whereby the upper and lower well zones 24 and 25, respectively, may be produced simultaneously or alternatively as desired. Control of such production, fobviously, is obtained through vertical movement of the power tubing 45, as described above. v

Although I have shown and described a preferred embodiment of my invention, it will be understood that certain parts and elements thereof are merely representative of other parts and elements which may be substituted therfor without departing from the spirit of theinvention, and consequently I do not intend to be limited to the embodiment shown, but desire to be afforded the full scope of thefollowing claims.

I claim as my invention:

1. In a fluid-operated well pumping device, the combination of: packer means adapted to be set in a well between an upper and a lower producing well stratum so as to separate the well int'o an upper well zone communicating with said upper stratum and a lower well zone communicating with said lower stratum; fluid-operated pumping means associated with said packer means and having a pump inlet, said pumping means being adapted to pump well liquid upwardly through said well; power tubing extending downwardly in said well and connected to said pumping means and adapted to supply operating fluid thereto; and means for opening communication between said pump inlet and either of said zones selectively, including means for moving said power tubing vertically in the well so as to move said pumping means relative to said packer means.

2. In a well pumping device, the combination of: packer means adapted to be set in a well between an upper and a lower producing well stratum so as to separate the well into an upper well zone communicating with said upper stratum and a lower well zone communicating with said lower stratum; a production tubing extending down- 10 wardly in said well; pumping means in said production tubing and having a pump inlet, said pumping means being adapted to pump well liquid upwardly through said production tubing; power tubing extending down into said well and connected to said pumping means to supply operating fluid thereto; and means for opening communication between said pump inlet and either of said zones selectively, including means for moving mechanically one of said tubings relative to said packer means. v -3. In 'a fluid-operated well pumping device, the combination of: packer means adapted to be set in a well between an upper and a lower producing well stratum so as to separate the well into an upper well zone communicating with said upper stratum and a lower well zone communicating with said lower stratum; pumping means associated with said packer means and having a pump inlet, said pumping means being adapted to pump well liquid upwardly through said well; power tubing extending downwardly in said well and connected to said pumping means to supply operating fluid thereto; and means for opening communication between said pump inlet and either of said zones selectively, including means for moving mechanically said power tubing ver tically in the well so as to move said pumping means relative to said packer means.

4. In a well device, the combination of: first packer means adapted to be set in a well between an upper and a ,lower producing well stratum so as to separate the well into an upper well zone communicating with said upper stratum and a lower well zone communicating with said lower stratum; second packer means adapted to be set in the well to form a reservoir zone thereabove separated from said upper and lower zones by said second packer means; and means for selectively opening communication between said reservoir zone and said upper well zone and said lower well zone.

5. In a well pumping device, the combination of: first packer means adapted to be set in a well between an upper and a lower producing well stratum so as to separate the well into anupper well zone communicating with said upper stratum and a lower well zone communicating with said lower stratum; second packer means adapted to be set in the well to form a reservoir zone thereabove separated from said upper and lower zones by said second packer means; means for selectively opening communication between said reservoir zone and said upper well zone and said lower well zone; and pumping means having a pump inlet communicating with said reservoir zone, said pumping means being adapted to pump well fluid from said reservoir zone upwardly through the well.

6. In a well pumping device, the combination of: first packer means adapted to be set in a well between an upper and a lower producing well stratum so as to separate the well into an upper well zone communicating with said upper stratum and a lower well zone communicating with said lower stratum: second packer means-adapted to be set in the well to form a reservoir zone there-- above separated from said upper and lower zones by said second packer means; means for selectively opening communication between said reservoir zone and said upper well zone and said lower well zone; and pumping means having a pump inlet communicating with said reservoir zone, said pumping means being adapted to pump well fluid from said reservoir zone upwardly through 7. In a'well pumping device, the combination of: production tubing adapted to be disposed in a well and adapted to receive therein a well pump; tubular means connected to the lower end of said production tubing and extending downwardly therefrom; first packer means on said tubular means and adapted to form a fluid seal between said tubular means and the wall of the well to define a first zone above said first packer means; second packer means on said tubular means below said first packer means and adapted to form a second fluid seal between said tubular means and the wall of the well to define a second zone between said first and second packer means and to define a third zone below said second packer means; and passage means in said tubucasing head connected to the upper ends of said tubings, said casing head having a discharge port communicating with the interior of said production tubing and having an inlet port communieating with the interior of said power tubing, and

, rotatable means engaging the upper end of said lar means connecting said second and first zones,

and connecting said first and third zones.

8. In a well pumping device, the combination of: production tubing adapted to be disposed in a well and adapted to receive therein a well pump; tubular means connected to the lower end of said production tubing and extending downwardly therefrom; first packer means on said tubular means and adapted to form a fluid seal between said tubular means and the wall of the well to define a first'zone above said first packer means; second packer means on said tubular means below said first packer means and adapted to form a second fiuid seal between said tubular means and the wall of the well to define a second zone between said first and second packer means and to define a third zone below said second packer means; passage means in said tubular means connecting said second and first zones and connecting said first and third zones; and valve means in said tubular means and adapted to control the flow of fluid through said passage means.

9. In a well pumping device, the combination of: a'production tubing adapted to be extended downwardly into a well; a fluid-operated well pump in said production tubing; a power tubing extending downwardly into said production tubing and having its lower end connected to said pump to supply operating fluid thereto; and a power tubing and adapted when rotated to raise said power tubing relative to said production tubing.

11. In a well pumping device, the combination of a production tubing adapted to be extended downwardly into a well; a power tubing adapted to be extended downwardly into the well; a sta-' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,081,220 Coberly May 25, 1937 2,242,166 Bennett May 13, 1941 2,298,834 Moore Oct. 13, 1942 2,304,303 Ferguson Dec. 8, 1942 2,349,649 Chenault May 23, 1944 

